Review Sheet for Anatomy-Ch 17

Review Sheet:

Chapter 17:

The common components of blood are plasma, erythrocytes, leukocytes, and platelets.

The common main function of blood is distributing substances, regulates, blood levels, and protects the body.

The main components of plasma are nutrients, gases, hormones, wastes, and products of cell activity, ions, and proteins.

The formed elements are erythrocytes, leukocytes, and platelets.

Two of these three aren’t true cells. Erythrocytes have no nuclei or organelles, ad platelets are cell fragments. ONLY leukocytes are complete cells.

Most of the formed elements survive in the bloodstream for only a few days.

Most blood cells do not divide. Instead, they are continuously renewed by division of cells in red bone marrow, where they originate.

Erythrocytes or red blood cells are small cells, about 7.5 in diameter. They are shaped like biconcave discs—flattened discs with depressed centers—they appear lighter in color at their thin centers than at their edges. Mature erythrocytes are bound by a plasma membrane, but lack a nucleus and have essentially no organelles. The red blood cell protein functions in gas transport and maintain the plasma membrane or promote changes in the red blood cell shape. They lack mitochondria and generate ATP by anaerobic mechanisms; they do not consume any of the oxygen they are transporting, making them very efficient oxygen transporters.

Leukocytes or white blood cells are the only formed elements that are complete cells, with nuclei and usual organelles. Being less than 1% of total blood volume, they are far less numerous than red blood cells. Leukocytes are crucial to our defense against disease. They form a mobile army that helps protect the body from damage by bacteria, viruses, parasites, toxins, and tumor cells. White blood cells are able to slip out of the capillary vessels—a process called diapedesis—and the circulatory system is simply their means of transport to areas of the body where they are needed...